A proton is moving with a uniform velocity of `10^(6)m.s^(-1)` along the Y-axis, under the joint action of a magnetic field along Z-axis and an electric field of magnitude `2xx10^(4)V.m^(-1)` along the negative X-axis. If the electric field is switched off, the proton starts moving in a circle. The radius of the circle is nearly (given: `(e)/(m)` ratio for proton `~~10^(8)C.kg^(-1)`)

Options

A. 0.5 m
B. 0.2 m
C. 0.1 m
D. 0.05 m

Answer

A